Astronomers say a galaxy sitting 2.9 billion light years from earth busy pumping out huge amounts of ultraviolet radiation resembles those thought to have altered the entire universe just shortly after its birth.
The galaxy is "leaking" radiation through holes in its cold gas cover, they say, the same mechanism believed to have occurred in similar galaxies just a few hundred million years following the Big Bang that helped bring light to the early universe, they say.
The star-forming region of the galaxy named SDSS 0921+4509, in its emitting of radiation, is mimicking processes that would have ended the darkness that existed in the early universe by ionizing and breaking up hydrogen atoms.
In the early days of the universe, its hydrogen atoms had cooled until protons and electrons and paired up to make hydrogen gas neutral, so that it absorbed all radiation and made the period "dark" or unobservable to astronomers.
It would take a billion years and huge amounts of ultraviolet radiation to ionize hydrogen, scattering its electrons and making the universe "visible."
That event is considered central in this history of the universe.
Since those events cannot be observed directly, astronomers must look for similar processes in objects seen today -- such as J0921+4509.
For a typical galaxy, only about 1 percent of its ultraviolet radiation can escape the surrounding dust and neutral hydrogen.
However, J0921+4509 has around 21 percent of its ultraviolet radiation escaping into interstellar space, the researcher have reported in the journal Science.
So why can this particular galaxy have so much radiation?
"Swiss cheese," says study leader Sanchayeeta Borthakur at Johns Hopkins University in Baltimore, Md. The galaxy spawns lots of hot stars whose light and "winds" -- high-powered versions of our own sun's solar wind-punch holes in the haze of neutral hydrogen gas around the galaxy.
"The [extreme ultraviolet] photons escape through the holes," Borthakur says. The finding suggests those galaxies that reionized the universe were rapidly forming stars, although most were smaller.
The 21 percent level of energy being emitted by J0921+4509 was unexpected, say several scientists not involved directly in the study.
"That's quite high," says astronomer Brian Siana of the University of California, Riverside. "This is roughly the fraction that we think all galaxies in the early universe had to have in order to ionize the hydrogen in the intergalactic medium."
